Most ecommerce builds we inherit fall into one of three patterns. First, a buy-once Shopify theme that looked great in the demo and ships at Lighthouse 65 with five paid apps adding bloat by month six. Second, a WordPress site with WooCommerce bolted on, run through Elementor, that crashes the host every Black Friday. Third, a custom build done cheaply by a freelancer who used an outdated framework, no documentation, no test suite, and disappeared two years in. All three end with the same conversation: 'we need to rebuild'.
The fix is to take the platform decision seriously upfront. Shopify is the right answer for most product-led ecommerce brands under R50m revenue without complex B2B or subscription needs. Shopify Plus opens up B2B, subscription, multi-storefront, and checkout extensions. WooCommerce is right when you need WordPress-native editorial alongside your store, complex B2B pricing without Plus-tier costs, or full ownership without platform fees. Custom-built makes sense for businesses with catalogue and operational complexity neither handles cleanly, and the team to maintain it long-term.
Then build with discipline. Performance budget treated as a hard requirement, not a wish. SEO foundations deployed as part of the build, not after. Schema, internal linking patterns, sitemap structure, and Merchant Centre feed all wired up before launch. Conversions API set up server-side from day one so iOS, ad blockers, and third-party cookie deprecation do not eat your attribution. Most of the value of a senior ecommerce build is in the work nobody sees: the build is correct, so the next three years of marketing investment actually compounds.